JPH042499B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet feeding device for copying machines, printing machines, recording machines, and other machines equipped with a mechanism for transporting sheets (hereinafter referred to as copying machines).
In particular, the present invention relates to a sheet feeding device that feeds a sheet while correcting curls and the like occurring in the sheet.

Conventionally, in this type of apparatus, a sheet is guided into a nip between rollers and fed by the pair of rollers. However, when using such a pair of rollers, the sheet must be flat and not curled. For example, if a curled sheet is fed, the leading edge of the sheet may come into contact with the pair of rollers. There were problems such as the sheet not being immersed in the sheet and the sheet being unable to be fed even when the pair of rollers started rotating, or even if the sheet was being fed, the timing was delayed.

SUMMARY OF THE INVENTION In view of these points, it is an object of the present invention to provide a novel sheet feeding device that is improved.

Another object of the present invention is to provide a sheet feeding device that can reliably feed even curled sheets.

That is, the object of the present invention that can achieve the above object is to
a conveying rotary body that applies a conveying force to the sheet; and a planar guide surface that guides the sheet from the upstream side of the conveying rotary body to a position where it can come into contact with the conveying rotary body, and the guide surface is connected to the conveying rotary body. a guide means movable between a first position spaced apart from the conveyance rotor and a second position for pressing the sheet against the conveyance rotary body; and a guide means movable to the conveyance rotary body by the guide surface in the first position. the seat guided to the correct position,
a moving means for moving the guide surface so as to press the conveying rotor by moving the guide surface to a second position; a regulating means for regulating the guide surface and releasing the regulation when it is in a second position; and after the moving means moves the guide surface to the second position and presses the sheet against the stopped conveying rotary body, the conveying rotation A sheet feeding device comprising: a control means for controlling the body to rotate;

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the main part thereof. In the figure, 1 is a photosensitive drum that rotates in the direction of the arrow. The drum has a photoconductive layer. Note that a latent image forming means, a developing means, and a cleaning means for removing residual toner after transfer are omitted and not shown in the figure. On the other hand, a sheet material conveyed in synchronization with the image on the photosensitive drum 1 is inserted through the insertion opening 2 on the right side of the apparatus. The inserted sheet material 3 is placed between a lower guide plate 4 and a drive roller 5 as a conveyance rotating body on the lower side, and an upper guide plate 6 as a guide means on the upper side.
The leading edge of the sheet hits a stopper 7 as a regulating means and stops. By means of a copy switch located outside the apparatus, the sheet material 3 is guided by guide plates 8 and 9 through the rotation of a drive roller 5 and reaches a register roller 10. Then, the register 10 starts rotating in synchronization with the document feeding, and the transfer material 3 is guided by the guide plates 11 and 12 to reach the drum 1. A potential is applied by discharge from the corona discharger 13 to transfer the toner image on the drum 1 to the sheet material 3. After the transfer, the sheet material 3 is separated from the drum 1 by a separation belt 14, and transferred to a fixing means 16 by a conveyor belt means 15.
transported to. The sheet material 3 on which the toner image has been fixed via the fixing means 16 is placed on a tray 17 outside the machine.
It will be transported to

FIG. 2 is an enlarged sectional view showing details of the mechanism by which the sheet material starts to be fed. Sheet insertion slot 2
The tip of the sheet material 3 inserted from the stopper 7
It hits and stops. By pressing the copy start switch provided on the outside of the device, the gap between the drive roller 5 and the upper guide plate 6 is pulled by the electromagnetic solenoid 21 as a moving means, and the 20 is moved. The upper guide 6, which serves as a rotational fulcrum, moves toward the dotted line ₆₁ to press the sheet material 3 against the drive roller 5. Next, the rotation of the drive roller 5 is started in order to convey the sheet material 3, but at the same time, the electromagnetic solenoid 25 is attracted and the stopper 7 rotates to the dotted line ₇₁ with the drive roller shaft 51 as a rotational fulcrum, and the sheet material ₃ is conveyed. The material comes out of the conveyance path.

Simultaneously with the rotation of the drive roller 5, the sheet material 3 is pressed against the drive roller 5 by the upper guide plate 6, so that the sheet material 3 starts to be conveyed and reaches the register roller 10. At this time, in order to convey the sheet material 3, a guide plate 6
It is necessary for the drive roller 5 to have a friction coefficient that is sufficiently larger than the friction coefficient of .

The sheet material 3 that has reached the register roller 10 forms a loop of 3 ₁ and waits until the register roller 10 starts rotating, and then starts rotating in synchronization with the drum 1. After the copy operation is completed, the electromagnetic solenoid 21
and 25 are turned off, and the respective return springs 22, 2
7 returns to the initial state. Return springs 22, 27
One end is hung on shafts 23, 26 which are fixed to the device.

Next, the operation timing will be explained with reference to FIGS. 3 and 4. FIG. 3 is a timing chart thereof, and FIG. 4 is a block diagram thereof.

The sheet material inserted from the insertion port 2 hits the stopper 7, and the sheet material is stopped for a moment.

By pressing the copy switch, a control section serving as a control means is activated to rotate the main motor and start the copying operation.

At the same time, the solenoid 21 is also energized, and the guide 6
The leading end of the sheet presses the sheet material against the feed roller 5.

Next, after a slight delay due to the command from the control unit, solenoid 2
5 is energized, and the stopper 7 is released from the seat passage. At the same time, a clutch connected to the drive roller 5 is actuated, causing the roller 5 to rotate. The sheet material is conveyed to the register roller 10 and stops temporarily, but since the roller 5 is rotating, a loop is formed between the rollers, and when the roller reaches a certain loop amount, the rollers are synchronized with the inside of the device, and the register roller 1
The electromagnetic clutch connected to 0 is energized to rotate the register roller 10 and transport it into the apparatus. After the register roller 10 has been rotated for a certain period of time (after the sheet material has passed), the rotation is stopped by a command from the control section.

At the same time, solenoids 21 and 25 and the drive clutch
After that, the main motor also stops and returns to the initial state, completing the copying process.

As explained above, according to the configuration of the present invention, even if curls or the like occur in the sheet to be conveyed, it can be corrected and fed reliably, so that delays in sheet timing, poor feeding, etc. can be avoided. Prevented.

Further, since the guiding means is separated from the conveying means, even a sheet with a curled tip can be easily guided to a position where it can be conveyed. Further, the control means controls the moving means to move the guide surface to the second position and press the sheet against the stopped conveying rotary body, and then rotate the conveying rotary body, so that the sheet is skewed. can be prevented.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment to which the present invention is applied, FIG. 2 is an enlarged sectional view showing the main parts thereof, FIG. 3 is a timing diagram, and FIG. 4 is a block diagram. In the figure, 5 is a drive roller, 6 is an upper guide plate, and 7 is a stopper.

Claims (1)

[Scope of Claims] 1. A conveying rotary body that applies a conveying force to the sheet, and a planar guide surface that guides the sheet from the upstream side of the conveying rotary body to a position where it can come into contact with the conveying rotary body, a guide means movable between a first position where the guide surface is separated from the conveying rotary body and a second position where the sheet is pressed against the conveying rotary body; and the guide surface located at the first position. The sheet guided to a position where it can come into contact with the conveyance rotating body,
a moving means for moving the guide surface so as to press the conveying rotor by moving the guide surface to a second position; a regulating means for regulating the sheet and releasing the regulation when it is in a second position; and a regulating means for moving the guide surface to the second position and pressing the sheet against the stopped conveying rotary body, and then moving the sheet to the conveying rotating body. A sheet feeding device comprising: a control means for controlling a rotating body to rotate; 2. The sheet feeding device according to claim 1, further comprising registration rollers that temporarily prevent the leading edge of the sheet fed by the conveying rotary body to form a loop in the sheet. .